Distech Controls VA-180GN Series Hardware Installation Manual page 7

Calibration (VA-180GNX024P Only)
Calibration is required with modulating actuators, and before the
function check. Calibration must be performed manually.
Prior to calibrating, ensure that:
-
Actuator is properly connected to a valve.
-
Housing cover is removed.
-
Power is applied.
If required, calibration can be repeated any number of times.
To initiate the calibration process insert a flat-blade screwdriver into
the calibration slot to short out the two sides of the slot. See Figure 24.
Figure 24. Step 1—Bridge contact.
During calibration, the actuator detects the valve's end positions and
files the exact stroke in its internal memory. Calibration takes place in
three phases:
-
Actuator drives to H (1), retracting actuator stem. Detection of
0
upper end position.
-
Actuator drives to H (2), extending actuator stem. Detection of
100
lower end position.
-
The detected values are stored (3). Then the actuator follows the
applied control signal.
Observe the status indication (LED) during and after calibration. See
Figure 25
Table 1.
and
Figure 25. Step 2—Check LED.
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